Circulating tumor cells as early predictors of metastatic spread in breast cancer patients with limited metastatic dissemination

Table 1 Baseline patient and tumor characteristics stratified by circulating tumor cell count

Variable	Overall,N(%)	CTCs <5/7.5 ml,n(%)	CTCs ≥5/7.5 ml,n(%)	P-value
Overall population	492 (100)	303 (61.6)	189 (38.4)	-
Treatment strategy
Systemic treatment only	467 (94.9)	286 (94.7)	180 (95.2)	ns
Additional locoregional treatment	25 (5.1)^a	16 (5.3)	9 (4.8)	ns
Line of treatment
First	232 (47.2)	139 (45.9)	93 (49.2)	ns
Second or later	260 (52.8)	164 (54.1)	96 (50.8)	ns
Type of systemic treatment
Chemotherapy	376 (76.4)	218 (71.9)	158 (83.6)	0.0041
Endocrine therapy	103 (20.9)	73 (24.1)	30 (15.9)
Other	13 (2.7)	12 (4.0)	1 (0.5)
Number of metastatic sites
1	146 (29.7)	104 (34.3)	42 (22.2)	0.0077
2	145 (29.5)	89 (29.4)	56 (29.6)
≥3	201 (40.8)	110 (36.3)	91 (48.2)
Distribution of metastatic sites
Lymph nodes/soft tissues^b	58 (11.8)	48 (15.8)	10 (5.3)	0.0003
Bone^c	326 (66.2)	172 (56.8)	154 (81.5)	<0.0001
Viscera^d	306 (62.2)	184 (60.7)	122 (64.6)	ns
Brain^e	37 (7.5)	23 (7.6)	14 (7.4)	ns

^aAdditional locoregional treatments: surgery 15 (3.0%); radiation therapy 8 (1.6%); other 2 (0.4%). ^bLymph nodes/soft tissue only. ^cBone with or without other sites. ^dVisceral organs (including brain) with or without other sites. ^eBrain with or without other sites. CTCs, Circulating tumor cells; ns, Statistically nonsignificant.

ISSN: 1465-542X